One life per game = not at all doable. Its fine for games like AA because those are mostly mission oriented (i.e. Ranger team go and attack Terror team at compound and grab data or free hostages) and not with a battlefield environment with reinforcements etc. This is a given and a moot point.
Finding that sweet spot where the mod has realism yet keeps servers full and players interested is the obvious target. I dont think its that elusive actually. The players we want to fill our servers will be those who enjoy the realism and thus play realistically. The DOOM-ers probably wont hang around..unless we gets some converts.
Here's what I think in summation in regards to medics after reading all of the posts:
1) Medics lose defib paddles - get limited injectors and bandages.
2) Injectors used for unconscious or severly wounded players.
3) Bandages used for all wounds to stop bleeding because untreated wounds bleed off health slowly.
4) Arm hits cause aiming difficulties until treated.
5) Leg hits slow player or prevent running altogether (double tap W)
6) Torso hits cause endurance for runs to be used up faster (or prevent running)
7) Head shots (which in most cases would be fatal anyways) would cause blurred vision until treated aside from major healt hit.

Medics decide to use one of their injectors then bandage wounds.
9) Medics can only stop bleeding on themselves and not restore health (no self heal although could use injectors on self if one available - again limited supply)
10) Injectors only replenish a max of 1/3 health.
11) All triage combined can only restore 1/2 of damage (i.e. current wound total). This would be cumulative so eventually a soldier would not be able to get much out of triage.
12) Possible, medics can drag or carry incapacitated soldiers to cover OR give them smoke grenades to offer temp cover.
13) Some soldiers killed or damaged beyond help (arty - tank rounds - shot in head by enemy when laying on ground incapacitated - severe falls etc).
14) No more dropped run-over-and-pick-up health kits.
15) No more crates or vehicles that provide triage - must be recieved hands on.
and finally...
16) Increase incapacitated timer from 15 to say 20 or 25.
Complicated to program perhaps but playable in my humble opinion if it can be implemented.